package com.rykj.util;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

import java.util.Random;

/**
 * 随机验证码 生成器
 */
public class CodeManager {
    /*随机数数组 */
    private static final char[] CHARS = {'2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
    /*default settings */
    /*验证码默认随机数的个数 */
    private static final int DEFAULT_CODE_LENGTH = 4;
    /*默认字体大小 */
    private static final int DEFAULT_FONT_SIZE = 25;
    /*默认线条的条数 */
    private static final int DEFAULT_LINE_NUMBER = 0;
    /*padding值 */
    private static final int BASE_PADDING_LEFT = 10, RANGE_PADDING_LEFT = 15, BASE_PADDING_TOP = 15, RANGE_PADDING_TOP = 20;
    /*验证码的默认宽高 */
    private static final int DEFAULT_WIDTH = 100, DEFAULT_HEIGHT = 40;
    private static CodeManager sBmpCodeManager;
    /*settings decided by the layout xml */
    /*canvas width and height */
    private int width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT;
    /*random word space and pading_top */
    private int basePaddingLeft = BASE_PADDING_LEFT, rangePaddingLeft = RANGE_PADDING_LEFT, basePaddingTop = BASE_PADDING_TOP, rangePaddingTop = RANGE_PADDING_TOP;
    /*number of chars, lines; font size */
    private int codeLength = DEFAULT_CODE_LENGTH, lineNumber = DEFAULT_LINE_NUMBER, fontSize = DEFAULT_FONT_SIZE;
    /*variables */
    private String code;
    private int paddingLeft, paddingTop;
    private Random random = new Random();
    /*验证码图片 */

    public static CodeManager getInstance() {
        if (sBmpCodeManager == null) {
            sBmpCodeManager = new CodeManager();
        }
        return sBmpCodeManager;
    }

    public Bitmap createBitmap() {
        paddingLeft = 0;
        Bitmap bp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(bp);
        code = createCode();
        c.drawColor(Color.WHITE);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setTextSize(fontSize); /*画验证码 */
        for (int i = 0; i < code.length(); i++) {
            randomTextStyle(paint);
            randomPadding();
            c.drawText(code.charAt(i) + "", paddingLeft, paddingTop, paint);
        }
        //画线条 
        for (int i = 0; i < lineNumber; i++) {
            drawLine(c, paint);
        }

        c.save();//保存
        c.restore();// 
        return bp;
    }

    public String getCode() {
        return code;
    }

    //生成验证码 
    private String createCode() {
        StringBuilder buffer = new StringBuilder();
        for (int i = 0; i < codeLength; i++) {
            buffer.append(CHARS[random.nextInt(CHARS.length)]);
        }
        return buffer.toString();
    }

    //画干扰线 
    private void drawLine(Canvas canvas, Paint paint) {
        int color = randomColor();
        int startX = random.nextInt(width);
        int startY = random.nextInt(height);
        int stopX = random.nextInt(width);
        int stopY = random.nextInt(height);
        paint.setStrokeWidth(1);
        paint.setColor(color);
        canvas.drawLine(startX, startY, stopX, stopY, paint);
    }

    //生成随机颜色 
    private int randomColor() {
        return randomColor(1);
    }

    private int randomColor(int rate) {
        int red = random.nextInt(256) / rate;
        int green = random.nextInt(256) / rate;
        int blue = random.nextInt(256) / rate;
        return Color.rgb(red, green, blue);
    }

    //随机生成文字样式，颜色，粗细，倾斜度 
    private void randomTextStyle(Paint paint) {
        int color = randomColor();
        paint.setColor(color);
        paint.setFakeBoldText(random.nextBoolean()); //true为粗体，false为非粗体 
        float skewX = random.nextInt(11) / 10;
        skewX = random.nextBoolean()?skewX:-skewX;
        paint.setTextSkewX(skewX); //float类型参数，负数表示右斜，整数左斜 
        //paint.setUnderlineText(true); //true为下划线，false为非下划线 
        //paint.setStrikeThruText(true); //true为删除线，false为非删除线 
    }

    //随机生成padding值 
    private void randomPadding() {
        paddingLeft += basePaddingLeft + random.nextInt(rangePaddingLeft);
        paddingTop = basePaddingTop + random.nextInt(rangePaddingTop);
    }
} 
